The use of rifle scopes, shotgun scopes, spotting scopes, and related optics (generally referred to herein as “scopes” or “telescopic sights”) is well known in the prior art. A wide variety of designs have been developed for the fulfillment of countless objectives and requirements. Many common scopes are designed with variable magnification power capability, providing the ability to “zoom in” on an object or target (collectively referred to as “target” hereafter) viewed through the scope. The increase in magnification results in a corresponding decrease in the field of view through the scope, however. Accordingly, if one attempts to “zoom in” or increase the magnification without carefully maintaining the target in the center of the field of view, it is easy to lose sight of the target from the field of view. This results in having to reacquire a view of the target through the scope, sometimes only after first reducing the magnification power to increase the field of view, and often after moving one's eye away from the eyepiece (or ocular lens).
Many high quality variable magnification scopes require significant hand strength and force to rotate the magnification adjustment ring, usually located just forward of the eyepiece, especially those that are tightly sealed from the internal hydrogen gas and the atmosphere. Applying this force while attempting to maintain sight of the target through the scope can be challenging because the entire scope and/or rifle to which it is mounted is often moved about while the adjustment is made.
Others have addressed this issue by providing a manually-operated and remotely controlled adjustment system such as that shown in U.S. Pat. No. 5,276,554, issued to Theodore S. Nassivera on Jan. 4, 1994. In that system, manipulation of a mechanical linkage by the shooter's thumb operates the magnification adjustment of a rifle scope. A similar mechanical linkage device is shown in U.S. Pat. No. 5,528,847 issued to Timothy D. Fisher et. al. on Jun. 25, 1996.
Alternatively, others have attempted to retrofit a battery-powered motor onto a rifle scope to provide a motorized magnification adjustment means. U.S. Pat. No. 5,388,005 issued to Steven W. Wilson on Feb. 7, 1995 is one such example. The device shown therein is controlled by a switch that can be mounted somewhere on the stock of the rifle and interconnects the power source and motor by way of wires. U.S. Pat. No. 6,519,083 issued to James A. Heinrich on Feb. 11, 2003 shows another example. This reference shows a retro-fit device in which an electric motor is connected via a drive belt to the zoom adjustment ring of a rifle scope. This reference also discloses the use of a wireless radio frequency transmitter and receiver such that a controller may be placed on the forestock or pistol grip of the rifle in a location convenient to the marksman.
Each of these latter examples require that the marksman use and maintain a single, preselected hand position in order to control the scope adjustment.